"angry alienated element who feel hard-done-by"
They genuinely are hard done by, ever since the USA was founded - on slavery:
the descendants of slaves who were kidnapped and brought to the USA, where they were most brutally treated as property, to be whipped, rapd , tortured at the whim of their owners
Even after slavery was abolished, there were the infamous Jim Crow laws in the former slave states, to keep down African Americans
Even in the 1960s, there were actual laws in some states forbidding them to use certain toilets, places on buses, hotels etc
Since the Civil RIghts Acts were passed, the police, private prisons and the whole system of justice have been used to oppress black Americans and / or profit from them.
The numbers of black men killed by the polcie or imprisoned in the USA is horrific
Being killed by the police is actually one of the leading cases of death for black men
and no .... black men are not inherently criminal
Even now, a Republican politician can describe slavery as a "necessary evil" for the US economy at the time
The oppression of African Americans - and the genocide of Native Americans - have been a disgraceful stain on the USA since its formation